Analytical g-function for vertical geothermal boreholes with effect of borehole heat capacity

摘要: Abstract Thermal response factors, known as g-functions play an important role in design geothermal boreholes and ground heat exchangers (GHE). In this paper, a new analytical g-function is proposed to account for the effect of borehole capacity (BHC) on thermal response; quantitative BHC fluid temperature can be obtained by without needing transient resistance. Firstly, cylindrical source model considering was built conduct Laplace transform method. Then, models coupling with were investigate temperature. By comparing conventional g-functions, it found that agreed better experimental data than during short time. The largest relative error prediction U pipe GHE about 2.9% mean coaxial less 1%. Moreover, had especially significant influence at times weakened And larger was, smaller radius would be.